Simulation on Discharge Behavior of Contact Pairs of On-Load Tap-Changer in Oil

Abstract

Due to the large-scale integration of new energy, on-load tap-changers operate more frequently, which increases the probability of arc generation. Arc causes high temperature damage to on-load tap-changer, aging of insulating oil medium, decreasing of insulation performance and increasing of failure rate. Aiming at the switch sliding situation of the on-load tap-changer, this work studies the arc temperature distribution characteristics under different contact gap distances, different arc currents and different sliding speeds through finite element simulation. The research shows that with the increase of the gap distance, the contact area between arc and surrounding environment increases, the heat transfer of arc increases, and the distribution range of arc temperature expands. With the increase of arc current, the maximum temperature of arc also increases, and the radius of arc column increases until the arc breaks. The higher the sliding speed, the lower the arc temperature due to the cooling effect of insulating oil. The research results lay a foundation for further study on the temperature characteristics of on-load tap changer arc.